github.com/ovsinc/prototool@v1.3.0/internal/grpc/invocation_event_handler.go (about)

     1  // Copyright (c) 2018 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package grpc
    22  
    23  import (
    24  	"io"
    25  
    26  	"github.com/fullstorydev/grpcurl"
    27  	"github.com/golang/protobuf/jsonpb"
    28  	"github.com/golang/protobuf/proto"
    29  	"github.com/jhump/protoreflect/desc"
    30  	"go.uber.org/zap"
    31  	"google.golang.org/grpc/metadata"
    32  	"google.golang.org/grpc/status"
    33  )
    34  
    35  var jsonpbMarshaler = &jsonpb.Marshaler{Indent: "  "}
    36  
    37  var _ grpcurl.InvocationEventHandler = &invocationEventHandler{}
    38  
    39  type invocationEventHandler struct {
    40  	output io.Writer
    41  	logger *zap.Logger
    42  	err    error
    43  }
    44  
    45  func newInvocationEventHandler(output io.Writer, logger *zap.Logger) *invocationEventHandler {
    46  	return &invocationEventHandler{
    47  		output: output,
    48  		logger: logger,
    49  	}
    50  }
    51  
    52  func (i *invocationEventHandler) OnResolveMethod(*desc.MethodDescriptor) {}
    53  
    54  func (i *invocationEventHandler) OnSendHeaders(metadata.MD) {}
    55  
    56  func (i *invocationEventHandler) OnReceiveHeaders(metadata.MD) {}
    57  
    58  func (i *invocationEventHandler) OnReceiveResponse(message proto.Message) {
    59  	i.println(i.marshal(message))
    60  }
    61  
    62  func (i *invocationEventHandler) OnReceiveTrailers(s *status.Status, _ metadata.MD) {
    63  	if err := s.Err(); err != nil {
    64  		i.err = err
    65  	}
    66  }
    67  
    68  func (i *invocationEventHandler) Err() error {
    69  	return i.err
    70  }
    71  
    72  func (i *invocationEventHandler) marshal(message proto.Message) string {
    73  	s, err := jsonpbMarshaler.MarshalToString(message)
    74  	if err != nil {
    75  		i.logger.Error("marshal error", zap.Error(err))
    76  		return ""
    77  	}
    78  	return s
    79  }
    80  
    81  func (i *invocationEventHandler) println(s string) {
    82  	if s == "" {
    83  		return
    84  	}
    85  	if _, err := i.output.Write([]byte(s + "\n")); err != nil {
    86  		i.logger.Error("write error", zap.Error(err))
    87  	}
    88  }